Forest Surface Area Occupied by Monarch Butterfly Hibernation Colonies in December 2014

A new survey of migratory monarchs at their wintering habitat shows a 69% increase in the area they occupied this winter in relation to last year’s winter. Yet this is still the second smallest area occupied by these butterflies in Mexican sanctuaries since 1993.

Monarch butterflies, which hibernate in Mexico, migrate between 1,200 to 2,800 miles from Canada and the United States to establish their colonies in temperate forests in the outskirts of Michoacán and the State of Mexico. The forest area occupied by these colonies serves as an indirect indicator of the number of butterflies that come to Mexico.